Human airway epithelial cell cultures maintained at an air-liquid interface (ALI) recapitulate mucociliary differentiation found in vivo, regulating ion transport, mucin secetion and ciliated cell beating to reproduce mucociliary clearance mechanisms characterisitic of the native human mucosa. These cultures are an excellent model to study the role of CFTR, ENaC, nucleotide/nucleoside regulatory systems and their integrated function in health and disease as proposed in projects 1-4 of the current PPG, respectively. A Tissue Procurement and Cell Culture Core was established at the University of North Carolina in 1984, under the auspices of the CF Foundation, to provide standardized cell cultures to CF researchers. The Core has supported PPG projects since 2000 and has increased its output and capabilities to meet growing research demands. The Core routinely makes available cells and media that are unavailable and/or prohibitively expensive if purchased from commercial suppliers. The purpose of the present application is to provide continuity in the supply of airway specimens and large numbers of human airway epithelial cell cultures to PPG investigators, and to support the use of cultures in mechanistic studies. To accomplish these goals, we propose the following specific functions. 1) Tissue Procurement- Obtain nasal and bronchial tissues from normal, disease control, and CF humans as sources of airway epithelial cells and for acute ex vivo experiments, biochemical studies, in situ hybridization and immunohistochemistry. Characterize donors with respect to diagnosis, demographics, and clinical features relevant to research uses. 2) Cell Isolation and Culture- Isolate primary and passaged primary epithelial cells for distribution to project investigators. Maintain stocks of frozen cells and prepare media and substrates to support preparation of well-differentiated airway epithelial cultures as dictated by investigator needs. 3) Genetic Mainipulation of Cell Cultures- Provide support for adenoviral and retroviral expression of molecules under study by project investigators. Through these functions, and in conjunction with other Cores in this application, the Cell Culture Core will support research to better understand mechanisms underlying normal airway surface liquid homeostatsis, which is essential for healthy lungs.